SOB vs unpleasant person

SOB and unpleasant person both are nouns.

Word	Noun	Adjective	Verb	Adverb
SOB	Yes	No	No	No
unpleasant person	Yes	No	No	No

As nouns, unpleasant person is a hypernym of SOB; that is, unpleasant person is a word with a broader meaning than SOB:

SOB: insulting terms of address for people who are stupid or irritating or ridiculous
unpleasant person: a person who is not pleasant or agreeable

Other hypernyms of SOB include disagreeable person.

SOB (noun)	unpleasant person (noun)
insulting terms of address for people who are stupid or irritating or ridiculous	a person who is not pleasant or agreeable
a dyspneic condition